In this contribution, we present an in situ high temperature Al-27 and P-31 magic angle spinning (MAS) NMR study of binary and ternary phosphate glasses at temperatures above the glass transition temperature T-G. For binary phosphate glasses, xK(2)O-(1 - x)P2O5 and ternary aluminophosphate glasses 30K(2)O-xAl(2)O(3-)(70 - x)P2O5 with 7 < x < 15 dynamic exchange processes between the various phosphate species (and aluminate species) present in the glasses could be identified in the temperature range between TG and the maximum achievable temperature T-max of our high temperature MAS NMR setup, T-G < T < T-max. This observation indicates rapid P-O-P and P-O-Al bond formation and bond breaking in the (alumino)phosphate glasses. From a modeling of the temperature dependence of these exchange processes, the activation energy EA for the corresponding process could be determined. These local bond breaking and making processes are ultimately linked to the macroscopic viscous flow and may indeed form the basic microscopic local step of viscous flow.